Earnings rose 41 percent in the first quarter ended Sept. 30 over the same quarter a year earlier. Quarterly revenue rose to $339.7 million, an 8 percent increase over the year-ago quarter. ResMed's fiscal year ends on June 30.

ResMed makes devices to treat respiratory disorders such as sleep apnea and other sleep-disordered breathing ailments. Such conditions are associated with other ailments such as obesity and heart disease. The company says treating sleep-disordered breathing will save the health care system money.

Shares of ResMed closed down $1.42 Friday at $39.92.

With a market value of more than $5.6 billion, ResMed is one of the most highly valued public companies in San Diego County.

ResMed's board also declared a quarterly dividend of 17 cents per share.